Method of disassembling pipe sections in a well



Nov. 22, 1955 1.. K. MOORE 2,724,440

METHOD OF DISASSEMBLING PIPE SECTIONS IN A WELL Filed Aug. 15, 1952 Zfill/195M512 K. #0025 it INVENTOR P Prz kwwpw w 9m ATTORNEY5 2,724,440Patented Nov. 22, 1955 United States Patent OfiFice METHOD orDISASSEMBLINGPIPE SECTIONS I A WELL Lawrence K. Moore Natchez, Miss.Application August 15, 1952, Serial No. 304,470

1 Claim. Cl. 166-46) This invention relates to processes of methods forassembling or disassembling a pluralityof pipe sections cooperating tomake up a string of pipe. More particularly, theinvention has'referenceto a process of the type stated wherein fluid pressure is employedadvantageously to facilitate the assembly ordisassembly of the pipe.

The invention can be particularly used to advantage in oil, gas, orwater well operations, but as will become apparent from the descriptionto be provided hereinafter, the inventive process can also be used instringing pipe across streams, rivers, etc., as well as for unscrewingpipe in pipelines extended above ground.

In showing, hereinafter, how the process can be carried out, theillustration and description will be confined to the showing of a stringof pipe in a well, such as an oil well. It will be understood, however,that this showing is offered purely by way of one example of a length ofconnected pipe sections to which the process can be applied, and it isnot intended that the showing be restrictive of the uses to which theprocess might be put, except, of course, as necessarily required by theappended claims.

It is a common occurrence, in oil, gas, or water well operations, for astring ofpipe to become stuck at a location spaced a substantialdistance from the surface of the ground, and heretofore, the disassemblyof the unstuck or free portion of the pipe, from that portion which isstuck, has been attended by substantial inconvenience and loss of time.The common practice is to lower explosive to the point at which the pipeis to be backed otf. The explosive is then detonated to break the pipe.

. The broad object of the present invention is to provide an improvedmethod of assembling or disassembling pipe, which will not necessarilyrequire that successively following pipe sections be threaded orunthreaded into and out of engagement with one another, at each andevery joint and which, further, will not require the use of explosive inconnection with the removal of stuck pipe.

A more specific object is to devise a process of the character referredto wherein a fluid pressure can be employed to advantage, in such amanner as to permit joint rotation of all the connected pipe sectionsthat are free to rotate, relative to the stuck pipe section immediatelytherebelow, the process being adapted to permit the connected, free pipesections to be removed bodily from the hole in little more time than ispresently required to unthread a single section relative to anothersection to which it is connected.

Another object of importance is to provide a process or method of thetype stated which will permit the use of conventional parts of wellequipment, thus to reduce substantially the expense involved in carryingout the process.

Another object is to provide a method or process of assembling ordisassembling pipe which will be simple,

effective in practically all cases, and. capable of being carried out bya minimum number of workers.

Still another object of importance is to provide a process of the typestated in which any pressure fluid, such as air, steam, or water can beused.

Other objects will appear from the following description, the claimappended thereto, and from the annexed drawing, in which like referencecharacters designate like parts throughout the several views, andwherein:

Figure 1 is an elevational view, in which parts are broken away andother parts are shown in section, showing a string of pipe ready to bedisassembled through the medium of the process constituting the presentinvention; and

Figure 2 is a fragmentary sectional view through a section of said pipeand through a pressure plug used in carrying out the inventive method.

The reference numeral 10 has been applied in the drawings to designate aplurality of elongated pipe sec;

tions, adjacent sections being threadedly connected to coupling sleeves12.

This, considered per se, is a conventional showing,

The reference letter A has been applied to a stratum in which a portionof the string of pipe defined by the pipe sections 10, is stuck, and thereference letter. B

has been applied to a stratum immediately thereabove in which anotherportion of the pipe string is free to rotate. Heretofore, in such aneventuality, those pipe sections extending through the material B to theground surface are detached in successive, descending order, and as willbe appreciated this is a time consuming, laborious operation, this beingparticularly true when the string of pipe comprises a substantial numberof pipe sections.

As is usual, the uppermost section 10 has. threadedly engaged therewitha head 14, provided with an inlet check valve 16 and a pressure gauge18. Additionally, the head is providedwith a center opening at its upperend, receiving a gland or stufling box 20. All this is conventional, andas Will be noted, the process constituting the present invention is suchas to permit its applica tion to these conventionally formed andconventionally connected parts of a string of well pipe.

At C I have designated one of the coupling sleeves 12 connectedthreadedly to the upper end of the uppermost pipe section 10 of thosesections that are stuck. In accordancewith the process constituting thepresent Attached to the lower end of the line 22 is a cup-like;

plug or packer 24, the skirt of said plug being disposed in scalable,wiping contact with the inner surface of the string of pipe.

The plug 24 is dropped downwardly within the string of pipe until it isdisposed immediately above the coupling 12 located at the point C. Thisarrangement is shown in Figure 1.

As a next step in carrying out the process, the string of pipe is filledfrom the plug 24 to the head 14 with any suitable pressure fluid, suchas air, steam, or water.

The gland or stufling box is then tightened against the head 14to anextent suflicient to prevent leakage of the pressure fluid through thegland itself, or through the opening of the head 14 in which the glandis mounted.

The next step in carrying out the processis to apply fluid pressure withany conventional pump, not shown,

various factors, such as the diameter and thickness of the pipe sections10.

As will be noted, there will now be defined a pressure s am er. between.p g an he d he p s u within said chamber is such as to cause thatportion of the string or pipe extending between the plug and head tobecome rigid, to such, an extent as will effectively prevent any pipesection above the plug 24 from being unthreaded from a coupling sleeve12 attached thereto.

This result obtains by reason of the fact that there is greater pressurewithin the aforementioned pressure chamber, than there is exteriorly ofsaid. chamber, said greater pressure causing the threads, of the pipesections bounding the chamber to be expanded against their associatedcouplings 12. This causes, these particular sections, to beheld inengagement with their associated couplings far more tightly than theywould be were there no pressure inside the pipe string. In other words,there is established abnormal frictional, contact between the threads ofa particular or selected group, of pipe sections so that none of ,the,individual sectionsthereof will rotate relatively one, to the other whenthe selected or particular group of pipe sections are rotated as a unit.

However, below the plug 24, the pressure within the string of pipe is nogreater than the pressure outside the pipe, or is, at least,substantially less than the pressure within the pipe above the plug.When the process has been carried out to this extent, it is thennecessary only that the uppermost pipe section 10, to which the head 14QO lnected, be rotated. This will cause all the pipe sections down toand including that in which plug 24 isdisposed to be rotated as one.Thus, these several pipe sections will be immediately disconnected fromthat coupling 12 disposed. at the location C, thus to cause thestring ofpipe to be separated immediately at the proper point. The free pipesections, that is, those pipe sections above the upp rmost sectiondisposed in stratum A, are now removed readily from the hole, and can beindividually disconnected above ground as they are lifted. Thisoperation, as will be appreciated, is far more simple and is carried outwith substantially greater facility, than the conventional method ofunscrewing successive pipe sections at ever-increasing depths within thehole.

From the foregoing, it will be evident that there has been. provided amethod of disassembling from a string of threadedly connected pipesections, a selected group of pipe sections, the method includingintroducing fluid under pressure into the selected group of pipesections to establish abnormal frictional contact between the threads ofthe selected group of pipe sections and then rotating said group of pipesections in a direction to uncouple it from the entire string of pipesections. As previously pointed out, it is the abnormal frictionalcontact between the threads of the selected group of pipe sections thatmaintain the separate group as a rotatable unit so as tov uncouple h eed oup fro he s n p p ct n t he. desired location since the group ofpipe sections to be rotated as a unit is capable of predeterminedselection, and when the selected group of pipe sections is rotated in adirection to uncouple it from the string of pipe sec-. tions, i t willbe apparent that the next adjacent pipe section to the one end of theselected group to which it has a threaded engagement will not have'thisabnormal pressure established by introducing fluid under pressure intothe selected group of pipe sections so that the threaded con-. nectionat this point will be uncoupled in preference to any of'the pipesections in the selected group.

I believe it will be apparent that the process. can also be employedadvantageously to unscrew pipe if a seatis installed in the pipe at apredetermined depth, which seat would 'hold a drop plug instead of aplug loweredthrough the string of pipe on a w-i-reline 22. In such aninstance,

, 4 if the string of pipe becomes stuck and the pipe is to bedisassembled at the location C, the plug can b e dropped downwardlyinside the pipe, gravitating freely therein. Weights can be associatedwith the plug if desired, to assist the gravitational movement thereof.The plug would, in this instance, travel down the pipe until it lodgesin the seat, after which pressure; is applied to the inside of the pipeabove the plug in the manner hereinbetore described.

This, I believe, is sufiiciently obvious as not to require specialillustration herein, it being believed. that it is well within the skillof those experienced in this art to provide a seat of the type stated;

It is also thought apparent that the process described herein could beused not only for disassembling pipe, but for assembling pipe, it beingclear that a plurality of tln'eadedly connected pipe sections can beformed into P s re a in. he m nn r her i e ore de cr be and rotatedasone relative to. a pipe section with which they r t be s s t ay n t dha the RIQC c s be ed ut in a s mb ng o sa emhlins p p in P p ne abovero n h et e c ndit on a e such as to preclude ordinary assembly ordisassemhly methods. Still further, the process can be employed ad;vantageously in sending; pipe across, streams or rivers, underconditions in whichthe, body of water to be crossed prevents the use ofordinary assembly ordisassembly. methods.

Ot ses. I e e m ysge hemselv It s. l e e ha he n nti ni not nec s rilyconfined to the, specific use. r uses thereof described e, s nce tmaY et liz d f ny Purpo e to ich it may be suited. Nor is the invention to benecessarily limit to he. p fi s ru t ll s ra ed and. escribed, sincesuch construction is only intended to. be illustrative ot the principlesof operation and the means presently devised to carry out saidprinciples, it being sidere t a he inve on. c mpr he ds ny minor hangein on tr c ion h t may p rm tt d t in. t e scope of the appended claim.

What is claimed is z The method of; disassembling from a string ofthreadedly connected; pipe, sections disp in a Wel a selected r up n ne.sec i ns. which mp is mo n a fluid seal downwardly through said. stringto a selected loca tion' adjacentthe, lower end of; said, selected goup... ntrou in and. m intaining fluid under p ssure. in s idselectedgroup above; the, seal to cause an increased frica ionalmn ctipon t e hr a onne g n ivi u l Pipesections of the selected group and toprevent rotation thereof; relative. t one; another, and, rotating theselected erc p Qtn p sec i ns-asaw it. in a. direction o. o p it rom.the s rin Refer nces-.011. in the. fil of. h s pat n UNITED. STATES.PATENTS

